RB211-535E4B

[airbirduk]

How can you tell if an engine has dual rating?

For example if I have an RB211-535E4B sat in my shop and want to offer it out at as an RB211-535E4 can I?

Thanks.

[aeromech3]

Not specific to the -535's ; you need to look for a service bulletin which allows a re-classification; if performance changes are involved then it might require test cell recalibration before the purchase of the new data plate from the OEM, usually on condition the old one is returned.
The Aircraft Flight Manual specifies which alternative engines can be fitted and what conditions apply; a point sometimes overlooked when small operators order new aircraft; get as many derivative marks included in the FM, then say at a later engine change if -E4B is not available, an -E4 can be fitted but with these conditions...